package com.liuxia8.part7;

/**
 * 复用类
 * composition for code reuse
 * Created by weng.junjie on 2017/2/17.
 */
public class WaterSource {
    private String s;
    WaterSource(){
        System.out.println("water source !");
        s="constructed";
    }
    public String toString(){
        return s;
    }
}
